Pneumatic tire carcass building machine having a bead lock assembly and a method of using the same

ABSTRACT

A pneumatic tire carcass building machine has a cylindrical building drum adapted for forming thereon a tire carcass of rubberized cord plies. Bead portions of the tire carcass are made by forming bead ring receiving shoulders in a rubberized fabric ply or plies positioned on said drum at each side of said drum with shoulder forming means, abutting or seating annular bead rings with said bead ring receiving shoulders with bead ring seating or carrier means positioning and holding the bead rings concentrically with bead lock means, and wrapping edge portions of the ply around the bead rings with turnover means while maintaining the concentric position of the bead rings with the bead lock means. Preferably each bead lock means includes at least three bead clamps spaced radially about the shaft of the cylindrical drum in preferably symmetric array, which clamps are driven from preset retracted positions to preset extended positions where they concentrically position the bead rings during turnover of edge portions of the carcass ply or plies.

United States Patent Henley et al.

1451 Mar. 18, 1975 PNEUMATIC TIRE CARCASS BUILDING 372L600 3/1973 Cantarutti 1515/4111 MACHINE HAVING A BEAD LOCK 3.816218 6/1974 Felten l5o/40l ASSEMBLY AND A METHOD OF USING THE SAME Primary E.\'ammerCl1fton B. Cosby [75] Inventors: Virgil E. Henley; Steve Kovalchik,

Jr., bOtl'l of Akron, Ol'llO ABSTRACT v [73] Assigneez The General Tire & Rubber A pneumatic tire carcass building machine has a cylincompany, Akron Ohio drical building drum adapted for forming thereon a tire carcassof rubberized cord plies. Bead portions l l Flledi Sept- 17, 1973 of the tire carcass are made by forming bead ring [21] APPL NO; 398,052 receiying shoulders in a rubberized fabric ply or plies ps1t1oned on sald drum at each side of sa1d drum with shoulder forming means, abutting or seating [57] U S Cl 156/400 156/l32 l56/401 annular bead rings with said bead ring receiving 1 l56/403 156l416 shoulders with bead ring seating or carrier means 51 Int. Cl. B2911 17/22 Wsitioning and holding the bead P concentricfilly [58] Field of Search 156/400, 401, 398, 403, bead lock means W P edge P 4 5 41 27 Tv Of around the bead rmgs Wlth. t.UIl'lOVl means whlle mamtammg the concentric posltlon of the bead rings with the bead lock means. Preferably each bead l l References Cited lock means includes at least three bead clamps spaced UNITED STATES PATENTS radially about the shaft of the cylindrical drum in 3.035629 5/1962 Vanzo et al 156 415 x Preferably Symmetric y; which Clamps are driven 3.237,]99 2/1966 Brey 156/415 X from preset retracted posltrons to preset extended 3.265.549 8/1966 Woodhall et al. 156/416 X positions where they concentrically position the bead 3,28l.304 l0/l966 Black et ill rings during turnover of edge portions of the carcass 3 475254 10 1969 Henley 156 401 ply or pliw 1489.634 l/l970 Pizzo ct al. l56/4l5 X 3.698.987 10/1972 Woodhall et al. 156/398 1 Claim, 11 Drawing Figures so 15 I 17 1s 49 48 QT 45 if V H 46 d 1 [i v 0 46 1 1 1 i 42 1 4 43 34 l 1 i l a? as l l 29 e1 57 39 38 i i 3 58 W x v., 1 v

PATENTEDHAR I 81975 mmaz SHiEI 3 BF 3 RADIAL CENTERLINE mwQ s 11 tea 4 .70

PNEUMATIC TIRE CARCASS BUILDING MACHINE HAVING A BEAD LOCK ASSEMBLY AND A METHOD OF USING THE SAME FIELD OF THE INVENTION The present invention relates to an apparatus and method for building pneumatic tires.

BACKGROUND OF THE INVENTION Apparatus for building pneumatic tires are well known in the art. Typically tires of bias type have been built by the flat band" method utilizing equipment such as that described in U.S. Pat. Nos. 2,614,951, 2,614,952, 2,628,652, 3,171,769, 3,156,601 and 3,645,826, all of which are owned by the assignee of the present application. Typically tires of radial type have been built by the toric match" method using a method and equipment such as that described in U.S. Pat. No. 3,475,254, which is also owned by the assignee of the present application.

Pneumatic tires are generally comprised of a tire carcass, sidewall and tread portions. The carcass, which as the foundation structure for the tire, usually comprises one or more layers of rubberized cords called plies. The cords may be, for example, cotton, nylon, rayon, polyester, glass or metal. The carcass normally has a pair of annular bead portions at the ends thereof adapted to securely seat the tire on a rim portion of a wheel. The tread and sidewall portions are positioned over the tire carcass and cured or vulcanized along with the carcass. A breaker or belt assembly is sometimes provided between the carcass and tread portion and, depending on the type of tire being built, may be assembled with either the carcass or the tread. The sidewall and tread portions are formulated usually from natural and/or synthetic rubber modified by the addition of fillers, reinforcing agents, antioxidants and processing aids such as softeners, accelerators, activating agents and curing agents. A tread pattern is usually molded into the ground-engaging portion of the tread portion during the curing of the tire.

For a more detailed discussion of the techniques and apparatus used to build radial type tires as distinguished from those used to build bias type tires, attention is directed to the disclosure contained in the aforementioned U.S. Pat. No. 3,475,254.

The building techniques for both radial and bias type tires are, however, similar to a point, particularly in the building of the carcass portion. Building is commenced by placing one or more carcass plies around a cylindrical building drum so as to form an annular flat band with edge portions of band overhanging the ends of the drum. Then, the drum surface is uniformly radially expanded, to provide a bead ring receiving shoulder at each end of the drum. Thereafter, annular bead rings, which usually consist of essentially inextensible rubberized cords and/or wires are abutted or seated against said shoulders by bead ring seating or carrier means, and the edges of the band are then wrapped, typically by turnover means, around the bead ring and folded back on and stitched to the outer surface of the annular bands.

Relatively recently, the beadforming procedures have been improved such as by the use of inflatable turnover bladders and annular pushover rings to fold the edges of the rubberized cord plies more evenly and uniformly around the annular bead rings (see U.S. Pat.

No. 3,171,769 also owned by the assignee of the present invention). However, difficulties still remain in making thebead portions of the carcass concentric and/or coaxial. Also, even with improvements, the bead ring itself may still be eccentric and/or may twist, torque or move slightly during the turnover of the edge portions of the carcass band. The resulting tire thus possesses geometric and structural variations which can adversely affect its overall performance.

The present invention substantially reduces or eliminates such variations due to improper formation of the bead portions of the carcass by providing a way and means by which the bead rings are concentrically positioned and securely held while the bead portions of the tire carcass are formed.

SUMMARY OF THE INVENTION A pneumatic tire carcass is built on a machine comprising a cylindrical building drum rotatably mounted on a shaft. Formation of the tire carcass is commenced by placing around the building drum a rubberized cord ply or plies which overhang the ends of the building drum. The bead portions of the carcass are thereafter formed by first forming bead ring receiving shoulders in the cord ply or plies disposed on the building drum at the ends of the drum with shoulder forming means. Each shoulder forming means typically is a means for expanding the diameter of the building drum.

Bead rings are then abutted or seated against the bead ring receiving shoulders of the carcass band at the ends ofthe drum by bead setting and carrier means and then positioned and held concentrically with bead lock means, preferably by radially moving the bead lock means from a preset retracted position to a preset extended position. Turnover means positioned preferably axially beyond the ends of the building drum thereafter wrap the overhanging edge portions of the carcass ply or plies around the seated bead rings while the bead lock means maintains the bead rings concentrically positioned. Thereafter the edge portions of the plies can be stitched to the outer surface of the plies overlaying the building drum and other components of the tire carcass and tire can be assembled with the procedures varying with the type of tire being built.

Preferably each bead lock means at each end of the building drum includes at least three bead clamps spaced, preferably symmetrically about the shaft of the building drum, and drive means for simultaneously moving said bead clamps from their retracted positions to preset extended positions. In the extended positions, the bead clamps of each bead lock means concentrically position and hold an abutted or seated bead ring and maintain it in position while the turnover means wraps the edge portions of the rubberized fabric plies around a bead ring. In addition, it is preferred that the drive means include a rack and pinion mechanism at each bead clamp with the rack preferably adjustably fastened to the bead clamp, a power train transmission means at each bead clamp fastened typically by a shaft to the pinion of said rack and pinion mechanism, and a pneumatic means to drive said train transmission means and in turn move said bead clamps radially between said retracted positions and said preset extended positions.

Other details, objects and advantages of the invention" will become apparent as the following description of the present preferred embodiments thereof and present preferred methods of performing the same proceeds.

BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawing, the present preferred embodiments and present preferred methods of practicing the invention are illustrated in which:

FIG. 1 is a detailed partial cross-sectional view in elevation of a cylindrical building drum and turnover means of a pneumatic tire carcass building machine embodying the present invention;

FIG. 2 is a cross-sectional view in elevation taken along line IIII of FIG. 1;

FIG. 3 is a cross-sectional view in elevation taken along line III-III of FIG. 1;

FIG. 4 is a cross-sectional view in elevation taken along line IVIV of FIG. 3, and

FIGS. 5 through 11 are fragmentary cross-sectional views in elevation of a pneumatic tire carcass building machine in various stages of operation in accord with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is particularly described in reference to the pneumatic tire carcass building machine used in making radial tires as described and claimed in U.S. Pat. No. 3,475,254, which is owned by the assignee of the present application. This description is for purposes of illustration. The invention may be otherwise variously embodied in pneumatic tire carcass building machines used in making bias-type tires as described and claimed in U.S. Pat. Nos. 2,614,951, 2,614,952, 2,618,652, 3,171,769, 3,156,601 and 3,645,826 all of which are owned by the assignee of the present application.

Referring to FIG. 1, a partial cross-sectional view through the axial centerline of pneumatic tire carcass building machine is shown having a building drum having a substantially cylindrical outer surface 11 and having annular extensions 12 positioned axially at each side (or end) of the drum. Drum 10 is mounted in can tilever on rotatable tubular shaft 13 as described by reference in U.S. Pat. No. 3,475,254. Cylindrical surface 11 of drum 10 consists of a tubular shaped bladder 14 which, when non-inflated, is substantially flat and lies between two circumferential shoulder portions 15, and description and purpose of which is fully explained in U.S. Pat. No. 3,475,254. Annular extensions 12 have an outer cylindrical surface 16 consisting of turnover bladders 17, which, in coaction with portions of the bead ring seating or carrier means 18 (called annnular pushover rings) (see FIG. 11), provide turnover means to wrap edge portions of the rubberized fabric plies disposed on drum 10 about bead rings as fully described hereinafter. The details of the construction and operation of the turnover bladders and the bead ring carriers are fully described in U.S. Pat. No. 3,171,769 and form a part of the present invention only in combination with other elements of the present invention as explained hereinafter.

Referring again to drum 10, tubular drum shaft 13 is horizontally mounted in cantilever and rotatably driven by suitable means as described by reference in U.S. Pat. No. 3,475,254. Screw shaft 19 is axially positioned with drum shaft 13 and is provided with threads 20 on portions of the outer surface, said threads of opposite pitch being symmetrically disposed on either side of the radial centerline of drum 10 (see FIGS. 5 and 9 of U.S. Pat. No. 3,475,254). Screw shaft 19 is attached to shoulder portions 15 of drum 10 and to annular extension 12 by annular threaded collar 21 and annular slide mount 22 fastened together by cap screws 23 through slot 24. Shoulder portions 15 and annular extensions 12 are thus adapted to axially slide in unison on tubular drum shaft 13 in slot 24 between stops 25 and 26. And collar supports 27 and 28 of drum 10 and of annular extensions 12, respectively, are fastened to slide mount 22 by suitable means such as keys so that the collar supports transversely slide on tubular shaft 13 with the rotation of screw shaft 19. Suitable means such as a clutch (not shown) are provided for rotation of the two shafts 13 and 19 in unison when the clutch is engaged and for rotation of screw shaft 19 independently when the clutch is disengaged. By this arrangement, drum 10 with annular extensions 12 can be axially expanded and contracted as fully shown and described in U.S. Pat. No. 3,475,254, for the reasons there explained which do not form a part of the present inventive combination.

Extending outwardly within drum 10 from collar 27 are annular inner supports 29 at each shoulder of the building drum. Each inner support 29 in turn supports a drum expanding bladder 30. Each drum expanding bladder 30 is a radially reinforced tubular member extending circumferentially around the building drum, and when deflated, lies flat against cylindrical surface 31 forming an integral part of support 29. Each drum expanding bladder 30 has a valve stem 32 which is inserted into a passageway 33 within support 29 and which comminicates through air inlet 34 to a source of pressurized air. Bladders 30 on each shoulder of drum 10, when inflated, serve to increase the diameter of drum 10 (as shown in FIG. 6) to form shoulder receiving portions on each side of a rubberized fabric ply disposed on drum 10 as described hereinafter.

The outer surface of each drum expanding bladder 30 is in contact with a row of segments 35, each row being spaced in an equal distance from the radial centerline of drum 10. The segments 35 in each row are composed of relatively rigid, preferably metal elements which are relatively narrow in width compared to length, and which cooperatively define as substantially cylindrical surface concentrically disposed around shaft 13 of drum 10. Each segment 35 has two integral legs or projections 36 and 37 extending radially inwardly and terminating in loops 38 and 39, respectively. The loops 38 and 39 of the segments 35 define channels or grooves in which resilient means such as garter springs 40 and 41, respectively, are positioned. Garter springs 40 and 41 serve to urge the segments 35 radially inwardly and maintain bladder 30 flat against surface 31 when the bladder is deflated. Upon inflation of bladder 30, the segments 35 in each row are biased radially outward under tension by garter springs 40 and 41, with said bias movement limited by contact of loops 38 and 39 against inner cylindrical surfaces 42 and 43, respectively, of annular inner support 29. Annular inner support assembly 44 is fastened to and extends outwardly from integral collar support 28.

Each of segments 35 is also provided with a radially outwardly extending projection 45 which is rounded and which, in cooperation with the projections 45 of the other segments in each row, define the rounded circumferential shoulder portions of drum 10. Projections 45 terminate at a radially outward point which is substantially flush with the cylindrical outer surface 11 of drum 10 and of shaping bladder 14 when deflated.

Additionally, a plurality of arcuate shields 46 are disposed circumferentially around drum l0 abutting with and outside rows of segments 35 to cylindrically bridge the gap across the central position of the drum between the rows of segments 35 to provide a substantially solid inner support for the shaping bladder 14. The shields are adapted to slide over each other as drum 10 is axially expanded and collapsed. Also, projections 45 of segments 35 are undercut to form a circumferential groove at each row of segments into which the ends of shields 46 can slide when the two rows of segments 35 are moved axially toward each other to their innermost position. The details of the construction and operation of shields 46 are shown and described in U.S. Pat. No. 3,475,254 and form no part of the present inventive combination except to support rubberized fabric plies disposed on drum l0 and annular extensions 12 as hereinafter described.

Referring to the annular extensions 12, annular inner support assembly 44 is, as previously mentioned, fastened to and extend outwardly from each collar support 28, terminating in annular bladder support discs 47 and inner clamping rings 48. Support assemblies 44 are also disposed at each side or end of drum l0 symmetrically about the radial centerline of the drum. Outer bead 49 of each turnover bladder 17 is clamped in substantially airtight engagement between support assemblies 44 and disc 47, and inner bead 50 of each turnover bladder 17 is clamped in substantially airtight engagement between support assemblies 44 and rings 48. The clamping engagement is completed by positioning bolts 51 or other suitable fastening means in support assemblies 44 (see FIG. 4). Each bladder 17 is in communication through air passageway 52 and air inlet 53 in support assembly 44 with a source of pressurized air.

Referring particularly to FIGS. 2, 3 and 4, annular extension 12 also includes a bead lock or positioning means for concentrically positioning the bead rings and maintaining the bead rings in position during the turnover operation as hereinafter described. Specifically, three (or more) shafts 54 are positioned in openings and bearing means in support assemblies 44 preferably symmetrically about drum shaft 13. On the inboard side of support assemblies 44 at each shaft 54 is provided bead clamp 55 and a rack and pinion assembly 56 as best shown in FIG. 2. The pinion 57 of assembly 56 is fastened to shaft 54 by a key or other suitable means and is geared to rack 58 of assembly 56, which is fastened preferably adjustably to bead clamp 55 as shown in FIG. 2. Each bead clamp 55 extends radially outwardly in an axially outward bend 59 between drum l0 and extension 12 to circumvent the turnover bladder 17 while not interfering with the operation of building drum 10. Each bead clamp 55 terminates in a projection 60, which is substantially flush with the cylindrical outer surface 11 of drum l0 and of shaping bladder 14 and the cylindrical outer surfaces 16 of annular extensions and of turnover bladders 17, when both bladders are deflated and the bead clamp is in a retracted position.

On the outboard side of support assemblies 44 at each shaft 54 is provided a sprocket 61, or other suitable train transmission means, and a drive means 62 for simultaneously moving the bead clamps 55 from preset retracted positions to preset extended positions where the bead clamps concentrically position a bead ring as hereinafter described. This assembly is best seen by reference to FIG. 3. Drive means 62 consists of sprocket chain 63 positioned about the sprockets 61 and an air cylinder or other hydraulic means 64 to which the two ends 65 and 66 of the chain 63 are fastened. Air cylinder 64 is communicated to a suitable pressurized air source by air outlet 67, and has its housing fastened to support assembly 44 by adjustable bolts 68 or other suitable fastening means. Bead clamps 55 are thus simultaneously extended radially to a preset extended position (as shown in FIG. 2) by retracting the air cylinder 64, and simultaneously returned to preset retracted positions by extending the air cylinder 64. Retraetion of air cylinder 64 is limited by contacting the housing of the air cylinder with threaded stop 69.

Referring to FIGS. 5 through 11, the sequential operations of the above-described pneumatic tire carcass machine are shown. As shown in FIG. 5, an inner liner 70 of, for example, butyl rubber is disposed essentially symmetrically about the radial centerline of drum 10 over cylindrical surface 11 of drum 10 and cylindrical surfaces 16 of annular extensions 12 symmetrically about the radial centerline of drum 10 to commence the construction of, for example, a tubeless pneumatic tire. One or more plies 71 of rubberized fabric (two plies shown in FIG. 5) are then disposed essentially symmetrically on the cylindrical surfaces 11 and 16 over liner 70 so that the edge portions overhang sides or ends of the building drum as shown in FIG. 5.

As shown in FIG. 6, drum expanding bladders 30 at each shoulder of drum 10 are then simultaneously inflated to bias rows of segments 35 radially outward against garter springs 40 and 41 to form bead ring receiving shoulders 72 in the liner 70 and plies 71 at each side of drum 10. The outward movement of the segments 35 and in turn bladders 30 are limited by loops 38 and 39 of segments 35 contacting circumferential surfaces 42 and 43, respectively, of annular inner supports 29 and 44, respectively. At this stage, the diameter of the building drum 10 is larger than the diameters of both the annular extensions 12, with deflated turnover bladders l7, and the inextensible bead rings to be subsequently incorporated into the bead portions of the tire carcass.

As shown in FIG. 7, bead rings 73 surrounded by flippers 73A are abutted or seated against the bead ring receiving shoulders 72 at each side of the drum 10 by seating or carrier means 18. The bead rings 73, with their flippers assembled, are each placed on a thin cy' lindrical flange or series of pins 75 of carrier means 18 axially exterior of the annular extensions 12 at each end of the building machine. The annular carrier means 18 are thus moved axially inwardly over the deflated turnover bladders 17 to abut or seat the bead rings 73 against the bead ring receiving shoulders 72 at each side of the drum 10. After bead rings 73 are placed against receiving shoulders 72, the bead lock means are actuated to concentrically set the bead rings and annular carrier means 18 are again moved axially outwardly away from the drum 10 to clear the turnover bladder 17.

As shown in FIG. 8, the bead rings are concentrically set by actuating air cylinder 64 of the bead lock means to simultaneously move, via chains 63, sprockets 61 and rack and pinion assembly 56, bead clamps 55 radially outward from a preset retracted position to a preset extended position. In the extended position, the bead clamps 55 contact portions of liner 70 and plies 71 adjacent the bead ring receiving shoulders 72 and urge said portions against the bead rings 73 to concentrically position said bead rings relative to the drum shaft 13 and maintain a slight pressure on the bead rings 73 until edge portions of the liner 70 and plies 71 are wrapped around the bead rings as hereinafter described. The pressure applied by bead clamps 55 to the bead rings 73 should be sufficient to eliminate significant twisting and torqueing of the bead rings during turnover as hereinafter described.

As shown in FIGS. 9, and 11, edge portions 74 of liner 70 and plies 71 are wrapped around bead rings 73 while the bead ring is concentrically held in position by bead lock means and more specifically bead clamps 55. As can be seen in FIG. 9, initial inflation of turnover bladders 17 pulls edges 74 of the liner and plies radially outwardly and axially away from the building drum thereby effecting a tight fit of the rubberized fabric plies and liner around the inner circumference of the bead rings 73. Circumferentially extending ribs (not shown) molded into the outer surfaces of the turnover bladders 17 assist in providing a slip-resistant surface for this purpose. Continued inflation of the turnover bladders 17 as shown by FIG. 10 results in the edges 74 of the liner and plies being folded radially and in a direction toward the axis of drum 10.

As shown in FIG. 11, the bead ring carrier or seating means 18 is thereafter again moved axially toward drum 10 so that annular sleeves or annular pushover rings 76 of carrier means 18 contact and push turnover bladders 17 over drum 10. At the same time, bladders 17 are deflated to permit them to transverse axially inwardly and toward the radial centerlines of drum 10 and in turn wrap the edges 74 of the liner 70 and plies 71 back over the surface of the plies into tightly adhering positions to complete the formation of the bead portions of the tire. The carrier means 18 are then moved axially away from drum 10 to their retracted positions and turnover bladders 17 are permitted to return to their deflated positions over the annular surfaces 16 of extensions 12, respectively. Bead clamps 55 are also concentrically retracted by actuating air cylinder 64. Thereafter, the edges 74 of the liner 70 and plies 71 are mechanically stitched to the outer surface of the plies 71 utilizing mechanically actuated stitcher as described by reference in US. Pat. No. 3,475,254.

It should be noted that the completed bead portion assumes relatively the same position in the carcass at this state of the construction as it will assume in the finished carcass and subsequent pneumatic tire. No rotation or turning of the bead portions are needed during the subsequent shaping operations. After bead rings 73 are positioned and edge portions 74 wrapped and stitched down, additional rubberized components such as chafer strips are applied to the building drum over the plies and bead portions to complete the tire carcass. Also sidewall strips may be applied to the carcass at this stage.

Although the above sequence of operations were shown in FIGS. 6 through 11 at only one side of the building drum, it is understood that the same sequence of operations is being simultaneously performed at both sides (or ends) of the drum. The only difference is that the retracted position for the carrier means 18 at the outboard side of the building drum is with the carrier means pivoted to a horizontal position to allow removal of the finished carcass and/or tire from the building drum, while the carrier means at the inboard side remains in a vertical position when retracted.

The pneumatic tire can be subsequently finished on the building drum either (i) by applying the breakers and tread rubber in a flat band where the breakers are bias corded, or (ii) by inflating the carcass to a toric shape and subsequently applying the breakers and tread as an assembly where the breakers are circumferential-inextensible as described in US. Pat. No. 3,475,254. In either event, the present inventive combination and method are embodied.

While the presently preferred embodiments of the invention and presently preferred methods of performing them have been specifically described, it is distinctly understood that the invention may be otherwise variously embodied and used within the scope of the following claims.

What is claimed is:

1. A pneumatic tire carcass building machine comprising:

A. a cylindrical drum rotatably mounted on a shaft.

said drum adapted for building thereon a tire carcass of rubberized fabric plies;

B. shoulder forming means for forming bead ring receiving shoulders at each side of a rubberized fabric ply disposed on said cylindrical drum;

C. bead setting means for abutting bead rings with bead ring receiving shoulders at each side of a said ply formed by said shoulder forming means disposed exteriorly of said cylindrical drum;

D. turnover means for wrapping edge portions of a said ply disposed on said cylindrical drum about the bead rings abutted by the bead setting means disposed exteriorly of said cylindrical drum; and

E. bead lock means for concentrically positioning the bead rings abutted by the bead setting means while said turnover means wrap edge portions of a said ply disposed on said cylindrical drum around the bead rings to form the bead ring portions of the tire carcass each said bead lock including i. at least three bead clamps spaced radially about the shaft of the cylindrical drum to concentrically position, when in preset extended positions,

the bead rings while the turnover means wrap said edge portions of a said ply around said bead rings; and

ii. drive means for simultaneously moving said bead clamps from retracted positions to said preset extended positions said drive means including a. a. rack and pinion means at each bead clamp with the rack rigidly fastened to the bead clamp,

b. a power train transmission means at each bead clamp fastened to the pinion of said rack and pinion means, and

c. a hydraulic means to drive said train transmission means and in turn move said bead clamps radially between said retracted positions and 

1. A pneumatic tire carcass building machine comprising: A. a cylindrical drum rotatably mounted on a shaft, said drum adapted for building thereon a tire carcass of rubberized fabric plies; B. shoulder forming means for forming bead ring receiving shoulders at each side of a rubberized fabric ply disposed on said cylindrical drum; C. bead setting means for abutting bead rings with bead ring receiving shoulders at each side of a said ply formed by said shoulder forming means disposed exteriorly of said cylindrical drum; D. turnover means for wrapping edge portions of a said ply disposed on said cylindrical drum about the bead rings abutted by the bead setting means disposed exteriorly of said cylindrical drum; and E. bead lock means for concentrically positioning the bead rings abutted by the bead setting means while said turnover means wrap edge portions of a said ply disposed on said cylindrical drum around the bead rings to form the bead ring portions of the tire carcass each said bead lock including i. at least three bead clamps spaced radially about the shaft of the cylindrical drum to concentrically position, when in preset extended positions, the bead rings while the turnover means wrap said edge portions of a said ply around said bead rings; and ii. drive means for simultaneously moving said bead clamps from retracted positions to said preset extended positions said drive means including a. a rack and pinion means at each bead clamp with the rack rigidly fastened to the bead clamp, b. a power train transmission means at each bead clamp fastened to the pinion of said rack and pinion means, and c. a hydraulic means to drive said train transmission means and in turn move said bead clamps radially between said retracted positions and said extended positions. 